The present invention relates to packaging machines, and more particularly relates to automated packaging machines for filling container bottles with pills.
Pharmaceutical medicines and associated packaging apparatus are typically subject to relatively strict consumer protection guidelines. For example, pills, capsules, and the like, must be produced and packaged in such a way as to at least meet the minimum sterility requirements mandated by federal regulations. In addition, the pills should be delivered into the. packaging such that the contents accurately meet the claimed labelling xe2x80x9ccountxe2x80x9d, i.e., each package includes exactly the predetermined number of pills. Notwithstanding the above, it is also desired to package the product in a mass production operation to offset costs typically attributed to a labor intensive operation in order to provide an economic product.
In the past, pill filling machines have been proposed which provide automated bottle counts by filling a hopper with pills and causing a plurality of the pills to be caught by a pill capturing device, such as an array of rotary slats. The rotary slats drop the captured pills into a plurality of bottles disposed in alignment with the dropping pills. The bottles are distributed along an endless conveyor belt which is timed to advance and stop the bottles according to the filling operation.
Conventional pill capturing devices more particularly include a series of rotary slats each configured to receive, hold and move a plurality of capsules or pills along a closed path. The rotary slats are typically discs fixed on a rotatable shaft and having a plurality of openings in the peripheral surface thereof for capturing individual pills. Accordingly, the closed path is arcuate and generally disposed between a pill hopper and discharge area above the conveyor belt. By the rotary action of the slat, the pills move in a direction normal to the bottle advancing automated conveyor belt. The pill capturing device then generally discharges the pills by rotating the slats which move corresponding to the closed path such that they fall out of the respective openings at the filling station. The pills are often funneled through a chute which empties into a corresponding bottle.
The count, or number of pills in the bottle, is determined by positioning the bottles in the pill dropping zone for a predetermined time. The duration of the filling operation for each bottle corresponds to the number of openings in each slat which the machine is capable of delivering to the bottles per unit of time. The duration of the filling operation, speed of the rotary slats and configuration of the pill capturing device are used to calculate the count.
U.S. Pat. No. 3,139,713 to Merrill proposes a machine with a discharge chute which is divided into a number of discharge compartments corresponding to the number of bottles being filled at the filling operation. As described, each bottle is to be filled with a count of one hundred pills. Each discharge chute receives five pills from one row or flight of the pill capturing device when the capturing device reaches a discharge position. In order to complete the filling operation, each bottle in the row receives twenty of the 5-article carrying flights.
Similarly, U.S. Pat. No. 4,674,259 to Hills proposes a series of elongated slats with cavities for carrying tablets to a set of chutes. The chutes operate with reciprocating movement to deliver the pills between first and second rows of bottles positioned at the filling station.
Unfortunately, if the pill capturing device fails to capture a pill in each and every cavity or receptacle, or if a pill should mistakenly be diverted, at least one of the bottles can be improperly filled. The conventional solution to this problem is to situate an operator adjacent to the slats to ensure that each receptacle is filled with a pill. If a pill is missing, the operator manually places a pill in the receptacle. Such an approach involves labor costs and can be unsatisfactory for sterility purposes.
In addition, the accuracy of the count of each bottle is largely determined by the operator and, as such, a fully and consistently accurate count cannot be guaranteed. Accordingly, there is a great need for a device which provides an accurate count for each bottle but which takes advantage of the high speed and efficiency of a rotary slat apparatus.
These and other objects and advantages are met by the packaging apparatus of the present invention having a plurality of rotary slats, each of which is independently driven. A separate counting device is associated with each rotary slat for counting each pill as it falls from the slat into the container. As such, a positive count is provided for each container and improperly filled slats will not affect the total count for that container. If a particular container has a low count, the respective slat can be further rotated to fill the container. Because the slats are independently driven, the other slats can remain stationary to prevent overfilling.
In particular, the packaging apparatus comprises a reservoir configured to hold a plurality of randomly oriented pills and define at least one opening adjacent a lower portion thereof. The plurality of rotary slats each have a peripheral edge portion rotatable into the opening in the reservoir. The peripheral edge portions of the rotary slats each define a plurality of pill receptacles configured to capture an individual pill at a first position in the reservoir and release the pill at a second position outside of the reservoir.
A conveyor is configured to move a plurality of open containers along a predetermined path of travel and position a container adjacent a respective rotary slat to define a delivery path extending between the second position of the rotary slat and the container. The pills are released from the slat and fall along the delivery path into the corresponding container. The apparatus also includes a plurality of drive motors in driving engagement with each of the rotary slats for rotating the respective slat and a controller connected to each of the drive motors for independently controlling the drive motors such that the slats can be rotated for different durations.
Another aspect of the invention is a novel drive device for driving each of the rotary slats. The drive device includes a rotatable drive motor, a pair of drive shafts connected to the drive motor and a pair of drive wheels connected to a respective drive shaft. The drive wheels each have frustoconical drive surfaces which are engaged with corresponding frustoconical drive surfaces on opposite sides of the rotary slat. Accordingly, rotation of the drive motor causes rotation of the rotary slat. A pneumatic cylinder is provided behind the drive motor for advancing and pressing the spaced apart frustoconical drive wheels against the rotary slat. This allows quick disengagement of the drive device when a changeover of rotary slats is desired (such as when a differently sized pill is to be packaged). Also, the constant pressure allows for continual engagement of the drive wheels during operation, even if the wheels begin to wear.
The apparatus also advantageously includes the counting devices discussed above disposed along each of the delivery paths for counting pills delivered along the path such that the number of pills passing into each container can be positively determined. In a preferred embodiment, each counting device is disposed adjacent to the respective open container and includes a light source which generates a continuous beam of light across the delivery path and an opposing light receiver which senses when the light is interrupted by each pill passing into the container. In addition, the controller is also preferably connected to the counting devices, and an alarm is connected to the counting devices for creating an alarm signal when any one of the containers is not full.
Associated methods also form a part of the invention. A preferred method first includes capturing a plurality of pills in individual pill receptacles formed on a plurality of rotary slats. The rotary slats are rotated to a position where the pills are released from the receptacles thereby allowing the pills to fall from the receptacles into the containers and define a delivery path. As each pill falls along the delivery path of a rotary slat, it is counted to positively determine to the number of pills deposited into the respective container. In a preferred embodiment, the method also includes the step of rotating each of the rotary slats independently with a separate drive motor.
The foregoing and other objects and aspects of the present invention are explained in detail in the specification set forth below.